The present invention pertains, in general, to methods and apparatus for controlling the movement of wheeled vehicles of the type that ordinarily would be pushed or pulled by an operator, and, more particularly, to the application of such methods and apparatus to walking aids for weak but ambulatory people, and for apparatus for adjusting such walking aids to meet the particular and evolving needs of such people.
A wide range of structures have been devised to assist people who find it difficult to walk unaided, and who may be lacking in strength or manual dexterity. A commonly-used structure for this purpose, customarily referred to as a walker, is fabricated from tubing, has three or four vertical legs and at least one horizontal support bar, and is light-weight enough to enable the ambulatory person to move it between steps. Such structures require the user to manually grasp the walker, lift it, and move it forward a desired distance. The user then walks behind the structure to a position of greater stability near the walker.
In addition to providing a stable support for moving about, walkers are especially useful for ambulatory people who may have dizzy spells, for then the walker serves as a stable structure with which the person using the device may support himself or herself when needed. If the user stumbles, a fall may be avoided by quickly grasping the walker, and for these reasons, the stability of a walker is of utmost importance.
Walkers, as executed in the prior art, have some problems, however. A lightweight walker can be easy to lift, but because of its lightness, it may not be stable, whereas a heavy walker will be stable, but difficult to lift The operation of lifting and moving a conventional walker can make locomotion difficult, awkward, and unstable for people who are too weak to firmly grasp or to lift it, for during the time that the walker is being lifted and moved, the user is less stable even than would ordinarily be the case when standing alone and without external support. Thus, the act of lifting the walker can be a source of difficulty for the user.
To overcome this problem f walkers have been designed with wheels, some with motor-driven wheels, which allow the user to move the walker without having to lift it. However, wheels make the walker essentially unstable.
This problem has been recognized, and attempts have been made to lend stability by manually actuable, cable-operated hand brakes for the wheels on walkers. Again, however, the use of hand brakes presents its own problem, since the operator may be afflicted with arthritis or some other debilitating injury or illness which prevents or makes difficult the laborious operation of the brake and maintenance of the steady pressure required to operate it. These hand brakes are also not well suited for one needing a steadying support after a sudden stumble, since at such times, when one quickly reaches for the walker, one is unlikely to readily grasp the hand brake, which may be far in front of the user. Further, squeezing a brake may be uncomfortable or difficult to coordinate.
Attempts to improve the stability of walkers with wheels includes the use of various spring-loaded braking arrangements such as the so-called glide brakes which gradually, although inefficiently, brake the walker when weight or downward pressure is applied. In such devices, wheels may be mounted on telescoping legs which are spring-biased to move the wheels into contact with the ground to provide mobility for the walker. When the operator leans on the walker, the operator's weight overcomes the spring bias to telescope the wheel, allowing the walker leg to gradually contact the ground and provide a brake. Unfortunately, however, most of the "downward" force applied to a walker in motion is, in reality, a forward force. Therefore, such arrangements can be hazardous to the operator, since they do not respond to users' different characteristics and abilities, with the result that the walker can roll away from the operator if insufficient pressure is being applied, or may stop prematurely upon application of a light pressure. Many walkers use a combination of wheels and legs; for example, two legs at the rear of the walker and two wheels at the front, to prevent accidental rolling, but such walkers can be awkward to use, since they require some lifting and rolling at the same time.
Motorized walkers with motor driven wheels have been provided, and some walkers have a predetermined operation when switched on so that they will move only a preselected distance. However, such devices may be heavy, and thus dangerous, and further, they may essentially remove control of operation from the operator and may, if accidentally activated, present additional danger to the operator.
A still further problem with prior walking aids is their inability to provide for differing and changing needs. Individual's needs evolve as their conditions improve or deteriorate, but prior walkers have not been able to accommodate to such changes. As a result, a walker that is initially suitable for an individual may gradually become unsuitable over a period of time, nor can it always be used by another person, such as a friend or family member.
Accordingly, there exists a need for a walker which can be operated by the feeble or infirm and which can be easily, reliably, and selectively made stable or mobile, and which can be adjusted to meet evolving or different needs.